CVE-2025-20688 is a security vulnerability identified in several MediaTek wireless chipset models, including MT6890, MT7615, MT7622, MT7663, MT7915, MT7916, MT7981, and MT7986. The flaw exists within the WLAN Access Point (AP) driver, where an incorrect bounds check leads to an out-of-bounds read condition (classified under CWE-125). This vulnerability allows a local attacker with user execution privileges to read memory beyond the intended buffer boundaries. Notably, exploitation does not require user interaction, increasing the risk of automated or stealthy attacks. The affected software versions include SDK release 7.6.7.2 and earlier, as well as openWRT versions 19.07 and 21.02 that utilize these chipsets. The out-of-bounds read can result in local information disclosure, potentially leaking sensitive data from kernel or driver memory spaces. Although no known exploits are currently reported in the wild, the vulnerability's nature suggests that attackers could leverage it to gather confidential information that may facilitate further attacks or privilege escalation. The issue has been assigned the internal MediaTek issue ID MSV-3480 and patch ID WCNCR00418047, but no public patch links are provided yet. The vulnerability was published on July 8, 2025, and was reserved in November 2024. Since no CVSS score is available, a severity assessment is necessary based on impact and exploitability factors.

For European organizations, the impact of CVE-2025-20688 primarily revolves around confidentiality breaches due to local information disclosure. Enterprises relying on MediaTek chipsets in their wireless access points or embedded devices running affected SDK or openWRT versions could face risks of sensitive data leakage, including cryptographic keys, configuration data, or user information stored in memory. This could undermine network security, facilitate lateral movement within internal networks, or enable attackers to bypass security controls. The lack of required user interaction and the local execution privilege requirement mean that attackers with limited access—such as employees, contractors, or compromised internal hosts—could exploit this vulnerability without alerting users. This is particularly concerning for organizations with large deployments of IoT devices, wireless infrastructure, or embedded systems using these chipsets. Additionally, the vulnerability could be leveraged as a stepping stone for more severe attacks, including privilege escalation or persistent compromise. Given the widespread use of openWRT in European network devices and the prevalence of MediaTek chipsets in consumer and enterprise wireless hardware, the threat could affect a broad range of sectors including telecommunications, manufacturing, healthcare, and public administration.

To mitigate CVE-2025-20688, European organizations should: 1) Immediately inventory all devices and systems using the affected MediaTek chipsets and verify the firmware or SDK versions in use, focusing on SDK release 7.6.7.2 and earlier and openWRT 19.07 and 21.02 deployments. 2) Engage with device vendors and MediaTek to obtain and apply official patches or firmware updates addressing this vulnerability as soon as they become available. 3) Where patches are not yet available, consider isolating vulnerable devices on segmented networks with strict access controls to limit local attacker access. 4) Implement strict user privilege management to minimize the number of users with local execution rights on affected devices. 5) Monitor network and system logs for unusual local access patterns or memory-related errors that could indicate exploitation attempts. 6) For openWRT users, consider upgrading to newer, unaffected versions or applying community patches if official fixes are delayed. 7) Conduct regular security assessments and penetration tests focusing on wireless infrastructure to detect potential exploitation or information leakage. These steps go beyond generic advice by emphasizing precise inventory, vendor coordination, network segmentation, and proactive monitoring tailored to the specific nature of this vulnerability.